root
71 lines
1.1 KiB
Markdown
71 lines
1.1 KiB
Markdown
# UART Communication Plan
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## Overview
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The first hardware version will use UART over CAT5 between the Pico dashboard and the ESP32 controller.
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UART is simpler than RS-485 and should be reliable for the short cable run inside the Xterra.
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RS-485 remains a future fallback if testing reveals communication issues.
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## Architecture
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Pico Dashboard
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| UART over CAT5
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ESP32 Controller
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Backup:
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WiFi HTTP API
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Fallback:
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RS-485 over CAT5
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## UART Wiring
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Pico TX -> ESP32 RX
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Pico RX <- ESP32 TX
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Ground <-> Ground
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## Planned Baud Rate
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Initial:
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115200
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Future Options:
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- 57600
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- 230400
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## Message Format
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Newline-delimited JSON
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Request:
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{"type":"status_request"}
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Response:
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{"type":"status_response"}
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## Failure Handling
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If communication is lost:
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- Dashboard shows warning
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- Last known values remain visible
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- Relay commands fail safely
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- WiFi backup may be attempted
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## Advantages
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- Fewer parts
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- Easier debugging
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- Easier wiring
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- No transceivers
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- No direction control
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- Works well for short runs
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## Future RS-485 Option
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If vehicle electrical noise causes issues, the transport layer can be switched to RS-485 without changing application logic.
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